This invention relates generally to conformance methods for oil or gas wells and particularly to early stage proactive conformance rather than late stage reactive conformance.
Liquid and gaseous hydrocarbons are extracted from the earth through wells that penetrate into or through hydrocarbon-bearing formations or reservoirs. Techniques for creating and using such wells are well-known. For a production well, such techniques are used during drilling, completing, and producing phases.
Drilling pertains to forming a borehole in the earth. Completing pertains to making the hole ready to allow desired hydrocarbons to flow up through it. Producing pertains to controlling and maintaining this flow.
There can be other fluids in the reservoir. Pertinent examples include water and unwanted gas. Amounts of these unwanted fluids relative to desired hydrocarbons and their locations relative to the reservoir can change over time (for example, by coning or channeling). When this occurs, one response is to provide a conformance treatment. In general, conformance is the management of unwanted water and gas in a well/reservoir.
Conformance treatments have been used near the end of, or otherwise late in, the production phase because that is when the adverse impact of unwanted water or gas has been most noticed (for example, a relatively large amount of water or unwanted gas begins to be produced). Although such late stage, or reactive, conformance treatment can be useful, it may be too late to reverse some or all detrimental reservoir conditions that may have resulted from the unwanted water or gas flow. These detrimental results may negatively affect the reservoir ultimate recovery factor.